Sampling
Techniques
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Nature and quality of sampling (e.g. cut channels, random
chips, or specific specialised industry standard measurement tools
appropriate to the minerals under investigation, such as down hole
gamma sondes, or handheld XRF instruments, etc). These examples
should not be taken as limiting the broad meaning of
sampling.
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A total of 53 hand-auger holes for
639m were drilled at the Kasiya Project to
obtain samples for quantitative mineralogical
determination.
Hand-Auger samples are composited
based on regolith boundaries and sample chemistry, generated by
hand-held XRF analysis.
Each 1m of sample is dried and
riffle-split to generate a total sample weight of 3kg for analysis,
generally at 1m-4m intervals. This primary sample is then split
again to provide a 1.5kg sample for both rutile and graphite
analyses.
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Include reference to measures taken to ensure sample
representivity and the appropriate calibration of any measurement
tools or systems used.
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Drilling and sampling activities are
supervised by a suitably qualified Company geologist who is present
at all times. All drill samples are geologically logged by the
geologist at the drill site/core yard.
Each sample is sun dried and
homogenised. Sub-samples are carefully
riffle split to ensure
representivity. The 1.5kg composite samples are then
processed.
An equivalent mass is taken from
each sample to make up the composite. A calibration schedule is in
place for laboratory scales, sieves and field XRF
equipment.
Placer Consulting Pty Ltd (Placer)
Resource Geologists have reviewed Standard Operating Procedures
(SOPs) for the collection and processing of drill samples and found
them to be fit for purpose. The primary composite sample is
considered representative for this style of rutile
mineralisation.
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Aspects of the determination of mineralisation that are
Material to the Public Report. In cases where 'industry standard'
work has been done this would be relatively simple (e.g. 'reverse
circulation drilling was used to obtain 1 m samples from which 3 kg
was pulverised to produce a 30 g charge for fire assay'). In other
cases more explanation may be required, such as where there is
coarse gold that has inherent sampling problems. Unusual
commodities or mineralisation types (e.g. submarine nodules) may
warrant disclosure of detailed information.
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Logged mineralogy percentages and
lithology information is used to determine compositing intervals.
Care is taken to ensure that only samples with similar geological
characteristics are composited together.
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Drilling
Techniques
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Drill type (e.g. core, reverse circulation,
open‐hole hammer,
rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core
diameter, triple or standard tube, depth of diamond tails,
face‐sampling bit
or other type, whether core is oriented and if so, by what method,
etc).
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A total of 53 hand-auger holes for
639m were drilled at the Kasiya Project to
obtain samples for quantitative
determination of recoverable rutile and Total Graphitic Carbon
(TGC).
Hand-auger drilling with 75mm
diameter enclosed spiral bits with 1-metre-long steel rods.
Each 1m of drill sample is collected into separate sample bags and
set aside. The auger bits and flights are cleaned between
each metre of sampling to avoid contamination.
Placer has reviewed SOPs for
hand-auger drilling and found them to be fit for purpose and
support the resource classifications as applied to the
MRE.
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Drill Sample
Recovery
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Method of recording and assessing core and chip sample
recoveries and results assessed.
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Samples are assessed visually for
recoveries. The configuration of drilling and nature of materials
encountered results in negligible sample loss or
contamination.
Samples are assessed visually for
recoveries. Overall, recovery is good. Drilling is ceased when
recoveries become poor once the water table has been
reached.
Auger drilling samples are actively
assessed by the geologist onsite for recoveries and
contamination.
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Measures taken to maximise sample recovery and ensure
representative nature of the samples.
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The Company's trained geologists
supervise drilling on a 1 team 1 geologist basis and are
responsible for monitoring all aspects of the drilling and sampling
process.
Hand-auger drilling samples are
retrieved and placed into large plastic bags. The bags are clearly
labelled and delivered back to the laydown at the end of shift for
processing.
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Whether a relationship exists between sample recovery and
grade and whether sample bias may have occurred due to preferential
loss/gain of fine/coarse material.
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No relationship is believed to exist
between grade and sample recovery. The high percentage of silt and
absence of hydraulic inflow from groundwater at this deposit
results in a sample size that is well within the expected size
range.
No bias related to preferential loss
or gain of different materials is observed.
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Logging
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Whether core and chip samples have been geologically and
geotechnically logged to a level of detail to support appropriate
Mineral Resource estimation mining studies and metallurgical
studies.
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Geologically, data is collected in
detail, sufficient to aid in Mineral Resource
estimation.
All individual 1-metre intervals are
geologically logged, recording relevant
data to a set log-chief template
using company codes. A small representative sample is collected for
each 1-metre interval and placed in appropriately labelled chip
trays for future reference.
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Whether logging is qualitative or quantitative in nature. Core
(or costean, channel, etc.) photography.
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All logging includes lithological
features and estimates of basic mineralogy. Logging is generally
qualitative.
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The total length and percentage of the relevant intersection
logged
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100% of samples are geologically
logged.
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Sub-sampling techniques and
sample preparation
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If
core, whether cut or sawn and whether quarter, half or all core
taken.
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N/A
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If
non-core, whether riffled, tube sampled, rotary split, etc. and
whether sampled wet or dry.
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Hand-auger samples from the 53 holes
drilled are dried, riffle split and composited. Samples are
collected and homogenised prior to splitting to ensure sample
representivity. ~1.5kg composite samples are processed.
An equivalent mass is taken from
each primary sample to make up the composite.
The primary composite sample is
considered representative for this style of mineralisation and is
consistent with industry standard practice.
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For all sample types, the nature, quality and appropriateness
of the sample preparation technique.
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Techniques for sample preparation
are detailed on SOP documents verified by Placer Resource
Geologists.
Sample preparation is recorded on a
standard flow sheet and detailed QA/QC is undertaken on all
samples. Sample preparation techniques and QA/QC protocols are
appropriate for mineral determination.
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Quality control procedures adopted for all sub-sampling stages
to maximise representivity of samples.
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The sampling equipment is cleaned
after each sub-sample is taken.
Field duplicate, laboratory
replicate and standard sample geostatistical analysis is employed
to manage sample precision and analysis accuracy.
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Measures taken to ensure that the sampling is representative
of the in situ material collected, including for instance results
for field duplicate/second-half sampling.
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Sample size analysis is completed to
verify sampling accuracy. Field duplicates are collected for
precision analysis of riffle splitting. SOPs consider sample
representivity. Results indicate a sufficient level of precision
for the resource classification.
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Whether sample sizes are appropriate to the grain size of the
material being sampled.
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The sample size is considered
appropriate for the material sampled.
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Quality of assay data and
laboratory tests
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The nature, quality and appropriateness of the assaying and
laboratory procedures used and whether the technique is considered
partial or total.
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Rutile
The Malawi onsite laboratory sample
preparation methods are considered quantitative to the point where
a non-magnetic mineral concentrate (NM) is generated.
Final results generated are for
recovered rutile i.e. the % mass of the sample that is rutile that
can be recovered to the non-magnetic component of a HMC.
The HMC is prepared via wet-table,
gravity separation at the Lilongwe Laboratory which provides an
ideal sample for subsequent magnetic separation and XRF.
All samples (incl. QA) included in
this announcement received the following workflow undertaken
on-site in Malawi;
· Dry
sample in oven for 1 hour at 105℃
· Soak
in water and lightly agitate
· Wet
screen at 5mm, 600µm and 45µm to remove oversize and slimes
material
· Dry
+45µm -600mm (sand fraction) in oven for 1 hour at
105℃
· Pass
+45µm -600mm (sand fraction) across wet table to generate a heavy
mineral concentrate (HMC)
· Pan
HMC to remove retained light minerals
· Dry
HMC in oven for 30 minutes at 105℃
· Magnetic separation of the HMC by Carpco magnet @ 16,800G
(2.9Amps) into a magnetic (M) and non-magnetic (NM)
fraction.
Bag NM fraction and send to Perth,
Australia for quantitative chemical and mineralogical
determination.
· The NM
fractions were sent to ALS Metallurgy Perth for quantitative XRF
analysis. Samples received XRF_MS.
Graphite
All samples are initially checked in
and processed to pulp at Intertek-Genalysis
Johannesburg.
The pulp samples are then dispatched
to Intertek-Genalysis Perth where they undergo TGC assay via method
C72/CSA.
A portion of each test sample is
dissolved in dilute hydrochloric acid to liberate carbonate carbon.
The solution is filtered using a filter paper and the collected
residue is the dried to 425°C in a muffle oven to drive off organic
carbon. The dried sample is then combusted in a Carbon/ Sulphur
analyser to yield total graphitic or elemental carbon (TGC).
The graphitic carbon content is
determined by eliminating other carbon forms from the total carbon
content. The addition of acid to the sample liberates carbon
dioxide thus removing carbonate carbon. Soluble organic carbon will
also be removed. Insoluble organic carbon is removed by heating the
samples at 425°C in an oxidising environment. The "dried"
carbon-bearing sample that is analysed in the resistance furnace is
considered to contain only graphitic carbon.
An Eltra CS-800 induction furnace
infra-red CS analyser is then used to determine the remaining
carbon which is reported as Total Graphitic Carbon (TGC) as a
percentage.
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For geophysical tools, spectrometers, handheld XRF
instruments, etc., the parameters used in determining the analysis
including instrument make and model, reading times, calibrations
factors applied and their derivation, etc.
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Acceptable levels of accuracy and
precision have been established. No handheld XRF methods are used
for quantitative determination.
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Nature of quality control procedures adopted (e.g. standards,
blanks, duplicate, external laboratory checks) and whether
acceptable levels of accuracy (i.e. lack of bias) and precision
have been established.
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Sovereign uses internal and
externally sourced wet screening reference material inserted into
samples batches at a rate of 1 in 20. The externally sourced,
certified standard reference material for HM and Slimes assessment
is provided by Placer Consulting.
Accuracy monitoring is achieved
through submission of certified reference materials
(CRM's).
ALS and Intertek both use internal
CRMs and duplicates on XRF analyses.
Sovereign also inserts CRMs into the
sample batches at a rate of 1 in 20.
Analysis of sample duplicates is
undertaken by standard geostatistical methodologies (Scatter, Pair
Difference and QQ Plots) to test for bias and to ensure that sample
splitting is representative. Standards determine assay
accuracy performance, monitored on control charts, where failure
(beyond 3SD from the mean) may trigger re-assay of the affected
batch.
Examination of the QA/QC sample data
indicates satisfactory performance of field sampling protocols and
assay laboratories providing acceptable levels of precision and
accuracy.
Acceptable levels of accuracy and
precision are displayed in geostatistical analyses.
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Verification of sampling
& assaying
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The verification of significant intersections by either
independent or alternative company personnel.
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Results are reviewed in
cross-section using Micromine software and any spurious results are
investigated. The deposit type and consistency of
mineralisation leaves little room for unexplained variance. Extreme
high grades are not encountered.
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The use of twinned holes.
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Twinned holes are not reported
here.
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Documentation of primary data, data entry procedures, data
verification, data storage (physical and electronic)
protocols.
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All geological field logging data is
collected in LogChief logging software. This data is then imported
to Datashed5 and validated automatically and then
manually.
Sovereigns' laboratory data is
captured onto paper templates or excel and transferred manually to
the database.
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Discuss any adjustment to assay data.
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QEMSCAN of the NM fraction shows
dominantly clean and liberated rutile grains and confirms rutile is
the only titanium species in the NM fraction.
Recovered rutile is therefore
defined and reported here as: TiO2 recovered in the +45
to -600um range to the NM concentrate fraction as a % of the total
primary, dry, raw sample mass divided by 95% (to represent an
approximation of final product specifications). i.e. recoverable rutile within the whole sample.
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Location of data
points
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Accuracy and quality of surveys used to locate drill holes
(collar and down-hole surveys), trenches, mine workings and other
locations used in Mineral Resource estimation.
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A Trimble R2 Differential GPS is
used to pick up the collars. Daily capture at a registered
reference marker ensures equipment remains in
calibration.
No downhole surveying is completed.
Given the vertical nature and shallow depths of the holes, drill
hole deviation is not considered to significantly affect the
downhole location of samples.
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Specification of the grid system used.
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WGS84 UTM Zone 36 South.
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Quality and adequacy of topographic control.
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DGPS pickups are considered to be
high quality topographic control measures.
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Data spacing &
distribution
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Data spacing for reporting of Exploration
Results.
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The hand-auger holes are spaced on a
on a regular grid which is deemed to adequately define the
mineralisation under investigation.
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Whether the data spacing and distribution is sufficient to
establish the degree of geological and grade continuity appropriate
for the Mineral Resource and Ore Reserve estimation procedure(s)
and classifications applied.
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The drill spacing and distribution
is considered to be sufficient to establish a degree of geological
and grade continuity appropriate for further future Mineral
Resource estimation.
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Whether sample compositing has been applied.
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Individual 1m intervals have been
composited, based on lithology for the 53 hand-auger
holes.
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Orientation of data in
relation to geological structure
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Whether the orientation of sampling achieves unbiased sampling
of possible structures and the extent to which this is known
considering the deposit type
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Sample orientation is vertical and
approximately perpendicular to the orientation of the
mineralisation, which results in true thickness estimates, limited
by the sampling interval as applied. Drilling and sampling are
carried out on a regular square grid. There is no apparent bias
arising from the orientation of the drill holes with respect to the
orientation of the deposit.
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If
the relationship between the drilling orientation and the
orientation of key mineralised structures is considered to have
introduced a sampling bias, this should be assessed and reported if
material.
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There is no apparent bias arising
from the orientation of the drill holes with respect to the
orientation of the deposit.
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Sample
security
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The measures taken to ensure sample security
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Samples are stored in secure storage
from the time of drilling, through gathering, compositing and
analysis. The samples are sealed as soon as site preparation
is complete.
A reputable international transport
company with shipment tracking enables a chain of custody to be
maintained while the samples move from Malawi to Australia or
Malawi to Johannesburg. Samples are again securely stored once they
arrive and are processed at Australian laboratories. A reputable
domestic courier company manages the movement of samples within
Perth, Australia.
At each point of the sample workflow
the samples are inspected by a company representative to monitor
sample condition. Each laboratory confirms the integrity of the
samples upon receipt.
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Audits or
reviews
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The results of any audits or reviews of sampling techniques
and data
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Richard Stockwell (resource CP) has
reviewed and advised on all stages of data collection, sample
processing, QA protocol and mineral resource estimation. Methods
employed are considered industry best-practice.
Malawi Field and Laboratory visits
have been completed by Richard Stockwell in May 2022. A high
standard of operation, procedure and personnel was observed and
reported.
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